Can individual states request UN monitoring of their elections/

[MineralMan]

4. To what end, really?

I mean, most states have laws stating who can be in polling places and where votes are counted. I don't know of any states that include international observers in those laws.

One thing's certain: If you're going to have those observers there, you're going to have to change the laws in each state. I don't see that happening in time for any election I'll probably be alive to vote in.

This sounds like another "wouldn't it be nice" thing that will never happen because the laws prohibit it. Perhaps such thing are a waste of time.